Hunting Dinosaurs in the Ancient Desert: The Glen Canyon Project

About 190 million years ago, a large chunk of the western United States was covered by a vast sand sea. Dunes stood hundreds of meters high, the climate was hot and dry, yet dinosaurs and other animals managed to survive here. The sands of this Sahara-like environment were eventually buried and became sandstone, which is visible in Dinosaur National Monument today. Here we refer to it as the Glen Canyon Sandstone, but in other areas it is sometimes called the Aztec, the Navajo, or the Nugget. This sea of sand lasted for 20-30 million years in the early Jurassic, but it is only about 600 feet thick. That might sound like a lot, but if you had 20 million years to make a stack of paper only 600 feet high, you'd have to put down only one single sheet of paper every ten years. And given that rate of accumulation, consider how remarkable it is to find anything at all from the animals and plants that lived during that period. Every fossil, no matter how small, is a phenomenal coincidence, an exception to the universal rule of destruction. For that reason alone they are worth recording and studying.

Farther south, in what is now New Mexico and Arizona, river deposits in some parts of the Glen Canyon unit reflect different, wetter environments along the southern border of the sand sea. That area has been extensively studied, and has produced numerous body fossils, including several species of dinosaur (herbivorous and carnivorous), crocodilians, pterosaurs, lizards, turtles, mammal-like reptiles, mammals, frogs and other amphibians, bony fish, and sharks. Encouraged by this success, paleontologists have been surveying the Glen Canyon in Dinosaur National Monument since 2006, looking for fossilized bones, footprints, or any other traces of life from this ancient, harsh ecosystem. The project is still ongoing, but several interesting sites have already been discovered. Click below to see some of the fossils found so far.

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The Ancient Desert

How do we know this area was a desert? What was it like?


Phil Bergman


Plants in a desert?!


Nobu Tamura


Footprints and bones!


Kevin Zim


Find out what scorpion tracks look like.



Other Reptiles

There's more than just the dinosaurs, you know!


National Park Service

Snapshot in Stone

An astonishing rock face tells the story of one night's activities.


National Park Service

Who's Who in the Glen Canyon Project?

Left Photo: Dan Chure, Paleontologist at Dinosaur National Monument

Right Photo: George Engelmann, Paleontologist at the University of Nebraska, Omaha


Exploring the Glen Canyon Sandstone in Dinosaur National Monument

The Sound of Silence trail gets you up close and personal with the Glen Canyon. The stone has weathered into gorgeous rounded bluffs that are definitely worth a trip. You can find information and directions to the trail on our Brochures page.

Geological Society of America

Official sponsor: Geological Society of America, GeoCorps Program

Last updated: December 19, 2022

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4545 Hwy 40
Dinosaur, CO 81610


435 781-7700

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